Porter Gillian, Wattam-Bell John, Bayer Antony, Haworth Judy, Braddick Oliver, Atkinson Janette, Tales Andrea
School of Psychology, University of Bristol, Bristol, UK.
Division of Psychology and Language Sciences, Faculty of Brain Sciences, University College London, London, UK.
Neurobiol Aging. 2017 Aug;56:17-24. doi: 10.1016/j.neurobiolaging.2017.03.004. Epub 2017 Mar 14.
The visual processing of complex motion is impaired in Alzheimer's disease (AD). However, it is unclear whether these impairments are biased toward the motion stream or part of a general disruption of global visual processing, given some reports of impaired static form processing in AD. Here, for the first time, we directly compared the relative preservation of motion and form systems in AD, mild cognitive impairment, and healthy aging, by measuring coherence thresholds for well-established global rotational motion and static form stimuli known to be of equivalent complexity. Our data confirm a marked motion-processing deficit specific to some AD patients, and greater than any form-processing deficit for this group. In parallel, we identified a more gradual decline in static form recognition, with thresholds raised in mild cognitive impairment patients and slightly further in the AD group compared with controls. We conclude that complex motion processing is more vulnerable to decline in dementia than complex form processing, perhaps owing to greater reliance on long-range neural connections heavily targeted by AD pathology.
阿尔茨海默病（AD）患者对复杂运动的视觉处理能力受损。然而，鉴于有报道称AD患者的静态形状处理能力受损，目前尚不清楚这些损伤是偏向于运动流，还是整体视觉处理普遍受损的一部分。在此，我们首次通过测量已知复杂度相当的成熟全局旋转运动和静态形状刺激的相干阈值，直接比较了AD、轻度认知障碍和健康衰老患者中运动和形状系统的相对保留情况。我们的数据证实，部分AD患者存在明显的特定于运动处理的缺陷，且该缺陷大于该组的任何形状处理缺陷。同时，我们发现静态形状识别能力下降更为渐进，与对照组相比，轻度认知障碍患者的阈值升高，AD组的阈值进一步升高。我们得出结论，与复杂形状处理相比，复杂运动处理在痴呆症中更容易衰退，这可能是由于对受AD病理严重影响的长距离神经连接的依赖性更强。
